package main.java.jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCDemo7 {
    public static void main(String[] args) {
        try (Connection connection = DBUtil.getConnection();){
            Statement statement = connection.createStatement();
            String sql = "SELECT COUNT(*) " +
                         "FROM class c " +
                         "JOIN student s ON c.id = s.class_id " +
                         "WHERE c.name = '1年级1班'";
            ResultSet rs = statement.executeQuery(sql);
            while(rs.next()){
                int count = rs.getInt("count(*)");
                System.out.println("一共"+count+"人");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}
